<!DOCTYPE html>
<html>
<head>
    <title>Vector Labels</title>
    <meta charset="UTF-8">
    <title>WMS GetFeatureInfo (Image Layer)</title>
    <script src="OpenLayers4.3.1/ol.js"></script>
    <link rel="stylesheet" href="OpenLayers4.3.1/ol.css" type="text/css">
    <style>
        h2 {
            font-size: 1.5em;
            line-height: 15px;
        }

        .scale-cnt {
            margin: 5px;
        }

        .edit-form-ctn {
        }

        .edit-form {
            float: left;
            margin: 5px;
            width: 230px;
            padding: 4px;
            border: 1px solid black;
        }

        .edit-form input[type="button"] {
            float: right;
        }

        .edit-form-elem label {
            display: block;
            float: left;
            width: 85px;
        }

        .edit-form-elem input[type="text"] {
            width: 60px;
        }

        .edit-form-elem select {
            width: 130px;
        }

        .edit-form br {
            clear: left;
        }

        .clearall {
            clear: both;
        }
    </style>
</head>
<body>
<div id="map" class="map"></div>

<div class="edit-form">
    <input id="refresh-points" type="button" value="Refresh" />
    <h2>Points</h2>
    <div class="edit-form-elem">
        <label>Text: </label>
        <select id="points-text">
            <option value="hide">Hide</option>
            <option value="normal">Normal</option>
            <option value="shorten" selected="selected">Shorten</option>
            <option value="wrap">Wrap</option>
        </select>
        <br />
        <label title="Max Resolution Denominator">MaxReso.:</label>
        <select id="points-maxreso">
            <option value="38400">38,400</option>
            <option value="19200">19,200</option>
            <option value="9600">9,600</option>
            <option value="4800">4,800</option>
            <option value="2400">2,400</option>
            <option value="1200" selected="selected">1,200</option>
            <option value="600">600</option>
            <option value="300">300</option>
            <option value="150">150</option>
            <option value="75">75</option>
            <option value="32">32</option>
            <option value="16">16</option>
            <option value="8">8</option>
        </select>
        <br />
        <label>Align: </label>
        <select id="points-align">
            <option value="center" selected="selected">Center</option>
            <option value="end">End</option>
            <option value="left">Left</option>
            <option value="right">Right</option>
            <option value="start">Start</option>
        </select>
        <br />
        <label>Baseline: </label>
        <select id="points-baseline">
            <option value="alphabetic">Alphabetic</option>
            <option value="bottom">Bottom</option>
            <option value="hanging">Hanging</option>
            <option value="ideographic">Ideographic</option>
            <option value="middle" selected="selected">Middle</option>
            <option value="top">Top</option>
        </select>
        <br />
        <label>Rotation: </label>
        <select id="points-rotation">
            <option value="0">0°</option>
            <option value="0.785398164">45°</option>
            <option value="1.570796327">90°</option>
        </select>
        <br />
        <label>Font: </label>
        <select id="points-font">
            <option value="Arial" selected="selected">Arial</option>
            <option value="Courier New">Courier New</option>
            <option value="Quattrocento Sans">Quattrocento</option>
            <option value="Verdana">Verdana</option>
        </select>
        <br />
        <label>Weight: </label>
        <select id="points-weight">
            <option value="bold">Bold</option>
            <option value="normal" selected="selected">Normal</option>
        </select>
        <br />
        <label>Size: </label>
        <input type="text" value="12px" id="points-size" />
        <br />
        <label>Offset X:</label>
        <input type="text" value="0" id="points-offset-x" />
        <br />
        <label>Offset Y:</label>
        <input type="text" value="0" id="points-offset-y" />
        <br />
        <label>Color :</label>
        <input type="text" value="#aa3300" id="points-color" />
        <br />
        <label title="Outline Color">O. Color:</label>
        <input type="text" value="#ffffff" id="points-outline" />
        <br />
        <label title="Outline Width">O. Width :</label>
        <input type="text" value="3" id="points-outline-width" />
    </div>
</div>

<div class="edit-form">
    <input id="refresh-lines" type="button" value="Refresh" />
    <h2>Lines</h2>
    <div class="edit-form-elem">
        <label>Text: </label>
        <select id="lines-text">
            <option value="hide">Hide</option>
            <option value="normal">Normal</option>
            <option value="shorten">Shorten</option>
            <option value="wrap" selected="selected">Wrap</option>
        </select>
        <br />
        <label title="Max Resolution Denominator">MaxReso.:</label>
        <select id="lines-maxreso">
            <option value="38400">38,400</option>
            <option value="19200">19,200</option>
            <option value="9600">9,600</option>
            <option value="4800">4,800</option>
            <option value="2400">2,400</option>
            <option value="1200" selected="selected">1,200</option>
            <option value="600">600</option>
            <option value="300">300</option>
            <option value="150">150</option>
            <option value="75">75</option>
            <option value="32">32</option>
            <option value="16">16</option>
            <option value="8">8</option>
        </select>
        <br />
        <label>Align: </label>
        <select id="lines-align">
            <option value="center" selected="selected">Center</option>
            <option value="end">End</option>
            <option value="left">Left</option>
            <option value="right">Right</option>
            <option value="start">Start</option>
        </select>
        <br />
        <label>Baseline: </label>
        <select id="lines-baseline">
            <option value="alphabetic">Alphabetic</option>
            <option value="bottom">Bottom</option>
            <option value="hanging">Hanging</option>
            <option value="ideographic">Ideographic</option>
            <option value="middle" selected="selected">Middle</option>
            <option value="top">Top</option>
        </select>
        <br />
        <label>Rotation: </label>
        <select id="lines-rotation">
            <option value="0">0°</option>
            <option value="0.785398164">45°</option>
            <option value="1.570796327">90°</option>
        </select>
        <br />
        <label>Font: </label>
        <select id="lines-font">
            <option value="Arial">Arial</option>
            <option value="Courier New" selected="selected">Courier New</option>
            <option value="Quattrocento Sans">Quattrocento</option>
            <option value="Verdana">Verdana</option>
        </select>
        <br />
        <label>Weight: </label>
        <select id="lines-weight">
            <option value="bold" selected="selected">Bold</option>
            <option value="normal">Normal</option>
        </select>
        <br />
        <label>Size: </label>
        <input type="text" value="12px" id="lines-size" />
        <br />
        <label>Offset X:</label>
        <input type="text" value="0" id="lines-offset-x" />
        <br />
        <label>Offset Y:</label>
        <input type="text" value="0" id="lines-offset-y" />
        <br />
        <label>Color :</label>
        <input type="text" value="green" id="lines-color" />
        <br />
        <label title="Outline Color">O. Color:</label>
        <input type="text" value="#ffffff" id="lines-outline" />
        <br />
        <label title="Outline Width">O. Width :</label>
        <input type="text" value="3" id="lines-outline-width" />
    </div>
</div>

<div class="edit-form">
    <input id="refresh-polygons" type="button" value="Refresh" />
    <h2>Polygons</h2>
    <div class="edit-form-elem">
        <label>Text: </label>
        <select id="polygons-text">
            <option value="hide">Hide</option>
            <option value="normal" selected="selected">Normal</option>
            <option value="shorten">Shorten</option>
            <option value="wrap">Wrap</option>
        </select>
        <br />
        <label title="Max Resolution Denominator">MaxReso.:</label>
        <select id="polygons-maxreso">
            <option value="38400">38,400</option>
            <option value="19200">19,200</option>
            <option value="9600">9,600</option>
            <option value="4800">4,800</option>
            <option value="2400">2,400</option>
            <option value="1200" selected="selected">1,200</option>
            <option value="600">600</option>
            <option value="300">300</option>
            <option value="150">150</option>
            <option value="75">75</option>
            <option value="32">32</option>
            <option value="16">16</option>
            <option value="8">8</option>
        </select>
        <br />
        <label>Align: </label>
        <select id="polygons-align">
            <option value="center" selected="selected">Center</option>
            <option value="end">End</option>
            <option value="left">Left</option>
            <option value="right">Right</option>
            <option value="start">Start</option>
        </select>
        <br />
        <label>Baseline: </label>
        <select id="polygons-baseline">
            <option value="alphabetic">Alphabetic</option>
            <option value="bottom">Bottom</option>
            <option value="hanging">Hanging</option>
            <option value="ideographic">Ideographic</option>
            <option value="middle" selected="selected">Middle</option>
            <option value="top">Top</option>
        </select>
        <br />
        <label>Rotation: </label>
        <select id="polygons-rotation">
            <option value="0">0°</option>
            <option value="0.785398164">45°</option>
            <option value="1.570796327">90°</option>
        </select>
        <br />
        <label>Font: </label>
        <select id="polygons-font">
            <option value="Arial">Arial</option>
            <option value="Courier New">Courier New</option>
            <option value="Quattrocento Sans">Quattrocento</option>
            <option value="Verdana" selected="selected">Verdana</option>
        </select>
        <br />
        <label>Weight: </label>
        <select id="polygons-weight">
            <option value="bold" selected="selected">Bold</option>
            <option value="normal">Normal</option>
        </select>
        <br />
        <label>Size: </label>
        <input type="text" value="10px" id="polygons-size" />
        <br />
        <label>Offset X:</label>
        <input type="text" value="0" id="polygons-offset-x" />
        <br />
        <label>Offset Y:</label>
        <input type="text" value="0" id="polygons-offset-y" />
        <br />
        <label>Color :</label>
        <input type="text" value="blue" id="polygons-color" />
        <br />
        <label title="Outline Color">O. Color:</label>
        <input type="text" value="#ffffff" id="polygons-outline" />
        <br />
        <label title="Outline Width">O. Width :</label>
        <input type="text" value="3" id="polygons-outline-width" />
    </div>
</div>
<div class="clearall"></div>
<script>
    var myDom = {
        points: {
            text: document.getElementById('points-text'),
            align: document.getElementById('points-align'),
            baseline: document.getElementById('points-baseline'),
            rotation: document.getElementById('points-rotation'),
            font: document.getElementById('points-font'),
            weight: document.getElementById('points-weight'),
            size: document.getElementById('points-size'),
            offsetX: document.getElementById('points-offset-x'),
            offsetY: document.getElementById('points-offset-y'),
            color: document.getElementById('points-color'),
            outline: document.getElementById('points-outline'),
            outlineWidth: document.getElementById('points-outline-width'),
            maxreso: document.getElementById('points-maxreso')
        },
        lines: {
            text: document.getElementById('lines-text'),
            align: document.getElementById('lines-align'),
            baseline: document.getElementById('lines-baseline'),
            rotation: document.getElementById('lines-rotation'),
            font: document.getElementById('lines-font'),
            weight: document.getElementById('lines-weight'),
            size: document.getElementById('lines-size'),
            offsetX: document.getElementById('lines-offset-x'),
            offsetY: document.getElementById('lines-offset-y'),
            color: document.getElementById('lines-color'),
            outline: document.getElementById('lines-outline'),
            outlineWidth: document.getElementById('lines-outline-width'),
            maxreso: document.getElementById('lines-maxreso')
        },
        polygons: {
            text: document.getElementById('polygons-text'),
            align: document.getElementById('polygons-align'),
            baseline: document.getElementById('polygons-baseline'),
            rotation: document.getElementById('polygons-rotation'),
            font: document.getElementById('polygons-font'),
            weight: document.getElementById('polygons-weight'),
            size: document.getElementById('polygons-size'),
            offsetX: document.getElementById('polygons-offset-x'),
            offsetY: document.getElementById('polygons-offset-y'),
            color: document.getElementById('polygons-color'),
            outline: document.getElementById('polygons-outline'),
            outlineWidth: document.getElementById('polygons-outline-width'),
            maxreso: document.getElementById('polygons-maxreso')
        }
    };

    var getText = function(feature, resolution, dom) {
        var type = dom.text.value;
        var maxResolution = dom.maxreso.value;
        var text = feature.get('name');

        if (resolution > maxResolution) {
            text = '';
        } else if (type == 'hide') {
            text = '';
        } else if (type == 'shorten') {
            text = text.trunc(12);
        } else if (type == 'wrap') {
            text = stringDivider(text, 16, '\n');
        }

        return text;
    };


    var createTextStyle = function(feature, resolution, dom) {
        var align = dom.align.value;
        var baseline = dom.baseline.value;
        var size = dom.size.value;
        var offsetX = parseInt(dom.offsetX.value, 10);
        var offsetY = parseInt(dom.offsetY.value, 10);
        var weight = dom.weight.value;
        var rotation = parseFloat(dom.rotation.value);
        var font = weight + ' ' + size + ' ' + dom.font.value;
        var fillColor = dom.color.value;
        var outlineColor = dom.outline.value;
        var outlineWidth = parseInt(dom.outlineWidth.value, 10);

        return new ol.style.Text({
            textAlign: align,
            textBaseline: baseline,
            font: font,
            text: getText(feature, resolution, dom),
            fill: new ol.style.Fill({color: fillColor}),
            stroke: new ol.style.Stroke({color: outlineColor, width: outlineWidth}),
            offsetX: offsetX,
            offsetY: offsetY,
            rotation: rotation
        });
    };


    // Polygons
    function polygonStyleFunction(feature, resolution) {
        return new ol.style.Style({
            stroke: new ol.style.Stroke({
                color: 'blue',
                width: 1
            }),
            fill: new ol.style.Fill({
                color: 'rgba(0, 0, 255, 0.1)'
            }),
            text: createTextStyle(feature, resolution, myDom.polygons)
        });
    }

    var vectorPolygons = new ol.layer.Vector({
        source: new ol.source.Vector({
            url: 'https://openlayers.org/en/v4.3.1/examples/data/geojson/polygon-samples.geojson',
            format: new ol.format.GeoJSON()
        }),
        style: polygonStyleFunction
    });


    // Lines
    function lineStyleFunction(feature, resolution) {
        return new ol.style.Style({
            stroke: new ol.style.Stroke({
                color: 'green',
                width: 2
            }),
            text: createTextStyle(feature, resolution, myDom.lines)
        });
    }

    var vectorLines = new ol.layer.Vector({
        source: new ol.source.Vector({
            url: 'https://openlayers.org/en/v4.3.1/examples/data/geojson/line-samples.geojson',
            format: new ol.format.GeoJSON()
        }),
        style: lineStyleFunction
    });


    // Points
    function pointStyleFunction(feature, resolution) {
        return new ol.style.Style({
            image: new ol.style.Circle({
                radius: 10,
                fill: new ol.style.Fill({color: 'rgba(255, 0, 0, 0.1)'}),
                stroke: new ol.style.Stroke({color: 'red', width: 1})
            }),
            text: createTextStyle(feature, resolution, myDom.points)
        });
    }

    var vectorPoints = new ol.layer.Vector({
        source: new ol.source.Vector({
            url: 'https://openlayers.org/en/v4.3.1/examples/data/geojson/point-samples.geojson',
            format: new ol.format.GeoJSON()
        }),
        style: pointStyleFunction,
        wrapX: false

    });

    var map = new ol.Map({
        layers: [
            new ol.layer.Tile({
                source: new ol.source.OSM()
            }),
            vectorPolygons,
            vectorLines,
            vectorPoints
        ],
        target: 'map',
        view: new ol.View({
            center: [-8161939, 6095025],
            zoom: 8
        })
    });

    document.getElementById('refresh-points')
            .addEventListener('click', function() {
                vectorPoints.setStyle(pointStyleFunction);
            });

    document.getElementById('refresh-lines')
            .addEventListener('click', function() {
                vectorLines.setStyle(lineStyleFunction);
            });

    document.getElementById('refresh-polygons')
            .addEventListener('click', function() {
                vectorPolygons.setStyle(polygonStyleFunction);
            });


    /**
     * @param {number} n The max number of characters to keep.
     * @return {string} Truncated string.
     */
    String.prototype.trunc = String.prototype.trunc ||
            function(n) {
                return this.length > n ? this.substr(0, n - 1) + '...' : this.substr(0);
            };


    // http://stackoverflow.com/questions/14484787/wrap-text-in-javascript
    function stringDivider(str, width, spaceReplacer) {
        if (str.length > width) {
            var p = width;
            while (p > 0 && (str[p] != ' ' && str[p] != '-')) {
                p--;
            }
            if (p > 0) {
                var left;
                if (str.substring(p, p + 1) == '-') {
                    left = str.substring(0, p + 1);
                } else {
                    left = str.substring(0, p);
                }
                var right = str.substring(p + 1);
                return left + spaceReplacer + stringDivider(right, width, spaceReplacer);
            }
        }
        return str;
    }
</script>
</body>
</html>